
<!DOCTYPE html>    
<html>    
<head>    
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">    
<script type="text/javascript">  
function preImg(sourceId, targetId) {  
    if (typeof FileReader === 'undefined') {  
        alert('Your browser does not support FileReader...');  
        return;  
    }  
    var reader = new FileReader();  
  
    reader.onload = function(e) {  
        var img = document.getElementById(targetId);  
        img.src = this.result;  
    }  
    reader.readAsDataURL(document.getElementById(sourceId).files[0]);  
}  
</script>  
</head>  
<body>  
<form action="">  
    <input type="file" name="imgOne" id="imgOne" onchange="preImg(this.id,'imgPre');" />  
    <img id="imgPre" src="" style="display: block;" />    
</form>  
</body>  
</html>  
